A survey of child car seats in Wiltshire has revealed nearly three quarters of those tested were either wrongly fitted or incompatible.
Wiltshire Council trading standards officers found 124 out of the 173 seats tested could fail in the event of an accident.
The council teamed up with independent experts last month to offer free checks at supermarkets in Chippenham, Devizes, Trowbridge and Salisbury.
Drivers with badly-fitted seats were shown how to make them safe.
Many of the problems related to buckles not being in the right place or twisted straps, while several car seats were found not to be compatible with the car.
In-car safety seat specialist Cathy Lyons, of V & C Consultants, said: “Parents and guardians need to buy the appropriate seat for the child and the car, it needs to be fitted correctly and checked regularly as seats will become loose in use.”
The best result, by a small margin, was in Chippenham where 68 per cent of car seats tested were fitted incorrectly, the worst was in Salisbury with 79 per cent. In Devizes and Trowbridge the figures were 72 and 73 per cent respectively.
In total, out of 173 car seats tested only 49 were correctly fitted, 72 per cent.
Council cabinet member for public protection Keith Humphries said: “We would like to thank all parents and carers for taking the opportunity to get their seats checked.
“The number of car seats found not to be fitted correctly certainly highlights the need for further events to reinforce the message to all motorists.”
Information on how to ensure your seat is fitted properly can be found at www.goodeggsafety.com.